fumarates and Kidney-Neoplasms

Biallelic inactivation of fumarate hydratase(FH) causes type 2 papillary renal cell carcinoma (PRCC2), uterine fibroids, and cutaneous leimyomas, a condition known as hereditary leiomyomatosis and renal cell cancer(HLRCC). The most direct effect of FH inactivation is intracellular fumarate accumulation. A majority of studies on FH inactivation over the past decade have focused on the theory that intracellular fumarate stabilizes hypoxia-inducible factor 1α(HIF1A) through competitive inhibition of HIF prolyl hydroxylases. Recently, a competing theory that intracellular fumarate activates nuclear factor (erythroid-derived 2)-like 2(NRF2) through post-translational modification of its negative regulator. Kelch-like ECH-associated protein 1(KEAP1) has emerged from a computational modeling study and mouse model studies. This review dissects the origin of these two governing theories and highlights the presence of chromatin-structure-regulated targets of transcription factors, which we refer to as "cryptic targets" of transcription factors. One such cryptic target is heme oxygenase I(HMOX1), the expression of which is known to be modulated by the gene product of SWI/SNF-related, matrix-associated, actin-dependent regulator of chromatin, subfamily a, member 4 (SMARCA4, also known as BRG1).

Topics: Animals; DNA Helicases; Fumarate Hydratase; Fumarates; Heme Oxygenase-1; Humans; Hypoxia-Inducible Factor 1, alpha Subunit; Intracellular Signaling Peptides and Proteins; Kelch-Like ECH-Associated Protein 1; Kidney Neoplasms; Leiomyomatosis; Neoplastic Syndromes, Hereditary; NF-E2-Related Factor 2; Nuclear Proteins; Procollagen-Proline Dioxygenase; Protein Processing, Post-Translational; Skin Neoplasms; Transcription Factors; Uterine Neoplasms

: Hereditary leiomyomatosis (HL) is an autosomal dominant condition due to a variety of fumarate hydratase (FH) mutations in which individuals tend to develop cutaneous leiomyomas, multiple uterine leiomyomas and are at risk for developing aggressive papillary renal cell carcinoma.. : A 26-year-old man with a past history of acute lymphoblastic leukemia (T-ALL) presented with numerous painful light brown papules and nodules spread all over his body except for the head, appearing since infancy. Similar lesions were present in his mother's family. A cutaneous biopsy revealed a cutaneous leiomyoma. His mother died from metastatic uterine neoplasia and his sister suffered from leiomyoma of the uterus. No renal cancer was reported in his family. A heterozygous pathogenic variant was detected in the FH gene.. : To our knowledge, this is the first case possibly linking HL and T-ALL through FH deficiency.

Topics: Adult; Carcinoma, Renal Cell; Female; Fumarates; Genetic Predisposition to Disease; Humans; Kidney Neoplasms; Leiomyomatosis; Male; Mutation; Precursor T-Cell Lymphoblastic Leukemia-Lymphoma; Skin Neoplasms; Uterine Neoplasms

Fumarate is an oncometabolite. However, the mechanism underlying fumarate-exerted tumorigenesis remains unclear. Here, utilizing human type2 papillary renal cell carcinoma (PRCC2) as a model, we show that fumarate accumulates in cells deficient in fumarate hydratase (FH) and inhibits PTEN to activate PI3K/AKT signaling. Mechanistically, fumarate directly reacts with PTEN at cysteine 211 (C211) to form S-(2-succino)-cysteine. Succinated C211 occludes tethering of PTEN with the cellular membrane, thereby diminishing its inhibitory effect on the PI3K/AKT pathway. Functionally, re-expressing wild-type FH or PTEN C211S phenocopies an AKT inhibitor in suppressing tumor growth and sensitizing PRCC2 to sunitinib. Analysis of clinical specimens indicates that PTEN C211 succination levels are positively correlated with AKT activation in PRCC2. Collectively, these findings elucidate a non-metabolic, oncogenic role of fumarate in PRCC2 via direct post-translational modification of PTEN and further reveal potential stratification strategies for patients with FH loss by combinatorial AKTi and sunitinib therapy.

Topics: Carcinogenesis; Carcinoma, Papillary; Carcinoma, Renal Cell; Cysteine; Drug Resistance, Neoplasm; Fumarate Hydratase; Fumarates; Humans; Kidney Neoplasms; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; PTEN Phosphohydrolase; Sunitinib

While performing surgical treatment of the localized form of renal cell cancer by means of open or laparoscopic partial nephrectomy, renal warm ischemia is an important issue. Using renal warm ischemia allows to prevent parenchymal bleeding, to optimize conditions for resection of the tumor and to increase significantly the efficiency of hemostasis. However, an important problem is the probability of ischemic hypoxic damage of the remaining part of the kidney tissue during renal warm ischemia and renal functional impairment in the postoperative period.. To compare nephroprotective activity of sodium fumarate, mannitol and furosemide using experimental model of 30- and 60-minute renal warm ischemia in rabbits.. The experiments were carried out on 360 conventional male-rabbits of the "Chinchilla" breed weighed 2,6+/-0,3 kg which were allocated into 10 groups. The control group No1 included intact animals, the control group No2 included the rabbits in which renal artery was not clamped. For the animals from the trial groups (No3-No10) the experimental model of 30- and 60-minute renal warm ischemia was used. In groups No3 and No4 no drugs were provided. Other rabbits undergone renal warm ischemia with a protection by sodium fumarate (groups No5 and No6 - 1,5 ml/kg IV), lasix (groups No7 and No8 - 3,0 mg/kg IV) and mannitol (No9 and No10 - 1,0 g/kg IV). The influence of renal warm ischemia on the renal tissue ultrastructure and the levels of NGAL, Cystatin-C and creatinine in blood and urine were studied.. During experimental pharmacologically uncorrected 30-minute renal warm ischemia in animals, edema of the terminal part of microvilli of the proximal tubules epithelium, an increase of lysosome number in the hyaloplasm of epithelial cells, appearance of flaky content of medium electronic density in the lumens of distal tubules and collecting tubules, as well as sharp peak-like increase of NGAL and cystatin-C in blood and urine were observed. Increasing the time of ischemia up to 60 minutes was accompanied by more severe disturbances. In groups where sodium fumarate, lasix and mannitol were used the observed ultrastructural disturbances were expressed to lesser extent, whereas sodium fumarate demonstrated the best nephroprotective activity. After using mannitol the severity of disturbances was less than in the groups where mannitol, lasix or sodium fumarate were not given. Lasix and sodium salt of fumaric acid showed a higher nephroprotective activity. The best results were received in the animals received sodium fumarate.. The studied drugs provided a nephroprotective effect regarding ischemia of rabbit kidney. The effect of sodium fumarate was the most pronounced, followed by furosemide and, to a lesser extent, mannitol. Use of sodium fumarate allows to protect and stimulate the kidney tissue effectively during oxygen deprivation under ischemic state.

Topics: Animals; Female; Fumarates; Furosemide; Humans; Ischemia; Kidney; Kidney Neoplasms; Lipocalin-2; Male; Mannitol; Rabbits; Warm Ischemia

Background Noninvasive in vivo detection of fumarate accumulation may help identify fumarate hydratase deficiency in renal cancer related to hereditary leiomyomatosis and renal cell carcinoma (HLRCC) syndrome. Purpose To investigate the feasibility of MR spectroscopy (MRS) in detecting elevated fumarate levels in HLRCC-associated renal cancers. Materials and Methods This study included an experimental xenograft mouse model and prospective clinical cohort. First, MRS was performed on patient-derived tumor xenograft models and control models to detect fumarate. Then, consecutive participants with clinical suspicion of HLRCC-associated renal tumors were enrolled. For the detection of fumarate, MRS results were classified as detected, borderline, undetected, or technical failure. The sensitivity, specificity, and accuracy of MRS for diagnosing HLRCC-associated renal cancer were assessed. The signal-to-noise ratio (SNR) of the fumarate peak was calculated and evaluated with receiver operating characteristic curve analysis. Results Fumarate peaks were detected at 6.54 parts per million in all three patient-derived xenograft models. A total of 38 participants (21 men; mean age, 47 years [range, 18-71 years]) with 46 lesions were analyzed. All primary HLRCC-associated renal cancers showed a fumarate peak; among the seven metastatic HLRCC-associated lesions, a fumarate peak was detected in three lesions and borderline in two. When only detected peaks were regarded as positive findings, the sensitivity, specificity, and accuracy of MRS at the lesion level were 69% (nine of 13 lesions), 100% (33 of 33 lesions), and 91% (42 of 46 lesions), respectively. When borderline peaks were also included as a positive finding, the sensitivity, specificity, and accuracy reached 85% (11 of 13 lesions), 88% (29 of 33 lesions), and 87% (40 of 46 lesions), respectively. The SNR of fumarate showed an area under the receiver operating characteristic curve of 0.87 for classifying HLRCC-associated tumors. Conclusion MR spectroscopy of fumarate was sensitive and specific for hereditary leiomyomatosis and renal cell carcinoma-associated tumors. © RSNA, 2022

Topics: Animals; Carcinoma, Renal Cell; Female; Fumarates; Humans; Kidney Neoplasms; Leiomyomatosis; Magnetic Resonance Spectroscopy; Mice; Neoplastic Syndromes, Hereditary; Prospective Studies; Skin Neoplasms; Syndrome; Uterine Neoplasms

Inherited pathogenic variants in genes encoding the metabolic enzymes succinate dehydrogenase (SDH) and fumarate hydratase predispose to tumor development through accumulation of oncometabolites (succinate and fumarate, respectively; ref. 1). Noninvasive. Magnetic resonance spectroscopy (. Here, we have demonstrated a proof of principle that. This study demonstrates that

Topics: Adult; Female; Fumarate Hydratase; Fumarates; Germ-Line Mutation; Humans; Kidney Neoplasms; Leiomyomatosis; Male; Middle Aged; Neoplastic Syndromes, Hereditary; Proton Magnetic Resonance Spectroscopy; Skin Neoplasms; Succinate Dehydrogenase; Uterine Neoplasms

Topics: Acetylcysteine; Antioxidants; Cell Line, Tumor; Fumarates; Glutathione; GPI-Linked Proteins; Humans; Intercellular Signaling Peptides and Proteins; Jurkat Cells; Kidney Neoplasms; NK Cell Lectin-Like Receptor Subfamily K; Oxidative Stress; Reactive Oxygen Species; Signal Transduction; Up-Regulation

An important context in which metabolism influences tumorigenesis is the genetic cancer syndrome hereditary leiomyomatosis and renal cell carcinoma (HLRCC), a disease in which mutation of the tricarboxylic acid cycle enzyme fumarate hydratase (FH) causes hyperaccumulation of fumarate. This electrophilic oncometabolite can alter gene activity at the level of transcription, via reversible inhibition of epigenetic dioxygenases, as well as posttranslationally, via covalent modification of cysteine residues. To better understand the potential for metabolites to influence posttranslational modifications important to tumorigenesis and cancer cell growth, here we report a chemoproteomic analysis of a kidney-derived HLRCC cell line. Using a general reactivity probe, we generated a data set of proteomic cysteine residues sensitive to the reduction in fumarate levels caused by genetic reintroduction of active FH into HLRCC cell lines. This revealed a broad up-regulation of cysteine reactivity upon FH rescue, which evidence suggests is caused by an approximately equal proportion of transcriptional and posttranslational modification-mediated regulation. Gene ontology analysis highlighted several new targets and pathways potentially modulated by FH mutation. Comparison of the new data set with prior studies highlights considerable heterogeneity in the adaptive response of cysteine-containing proteins in different models of HLRCC. This is consistent with emerging studies indicating the existence of cell- and tissue-specific cysteine-omes, further emphasizing the need for characterization of diverse models. Our analysis provides a resource for understanding the proteomic adaptation to fumarate accumulation and a foundation for future efforts to exploit this knowledge for cancer therapy.

Topics: Cell Line, Tumor; Cysteine; Fumarate Hydratase; Fumarates; Humans; Kidney Neoplasms; Leiomyomatosis; Neoplastic Syndromes, Hereditary; Skin Neoplasms; Uterine Neoplasms

Renal cell carcinomas (RCCs) are common cancers diagnosed in more than 350,000 people each year worldwide. Several pathways are de-regulated in RCCs, including mTORC1. However, how mTOR drives tumorigenesis in this context is unknown. The lack of faithful animal models has limited progress in understanding and targeting RCCs. Here, we generated a mouse model harboring the kidney-specific inactivation of Tsc1. These animals develop cysts that evolve into papillae, cystadenomas, and papillary carcinomas. Global profiling confirmed several metabolic derangements previously attributed to mTORC1. Notably, Tsc1 inactivation results in the accumulation of fumarate and in mTOR-dependent downregulation of the TCA cycle enzyme fumarate hydratase (FH). The re-expression of FH in cellular systems lacking Tsc1 partially rescued renal epithelial transformation. Importantly, the mTORC1-FH axis is likely conserved in human RCC specimens. We reveal a role of mTORC1 in renal tumorigenesis, which depends on the oncometabolite fumarate.

Topics: Animals; Carcinoma, Renal Cell; Cells, Cultured; Female; Fumarate Hydratase; Fumarates; Humans; Kidney Neoplasms; Male; Mechanistic Target of Rapamycin Complex 1; Mice; Mice, Inbred C57BL; Tuberous Sclerosis Complex 1 Protein; Up-Regulation

Topics: Animals; Epithelial-Mesenchymal Transition; Fumarate Hydratase; Fumarates; Humans; Kidney Neoplasms; Mice; Models, Biological

Germ line mutations of the gene encoding the tricarboxylic acid (TCA) cycle enzyme fumarate hydratase (

Topics: Amino Acid Sequence; Carcinoma, Renal Cell; Cell Line, Tumor; Cell Proliferation; Ferritins; Forkhead Box Protein M1; Fumarate Hydratase; Fumarates; Humans; Intracellular Space; Iron Regulatory Protein 2; Kidney Neoplasms; Leiomyomatosis; Models, Biological; NF-E2-Related Factor 2; Protein Biosynthesis; Signal Transduction; Succinic Acid; Transcription, Genetic

Mutations of the tricarboxylic acid cycle enzyme fumarate hydratase cause hereditary leiomyomatosis and renal cell cancer. Fumarate hydratase-deficient renal cancers are highly aggressive and metastasize even when small, leading to a very poor clinical outcome. Fumarate, a small molecule metabolite that accumulates in fumarate hydratase-deficient cells, plays a key role in cell transformation, making it a bona fide oncometabolite. Fumarate has been shown to inhibit α-ketoglutarate-dependent dioxygenases that are involved in DNA and histone demethylation. However, the link between fumarate accumulation, epigenetic changes, and tumorigenesis is unclear. Here we show that loss of fumarate hydratase and the subsequent accumulation of fumarate in mouse and human cells elicits an epithelial-to-mesenchymal-transition (EMT), a phenotypic switch associated with cancer initiation, invasion, and metastasis. We demonstrate that fumarate inhibits Tet-mediated demethylation of a regulatory region of the antimetastatic miRNA cluster mir-200ba429, leading to the expression of EMT-related transcription factors and enhanced migratory properties. These epigenetic and phenotypic changes are recapitulated by the incubation of fumarate hydratase-proficient cells with cell-permeable fumarate. Loss of fumarate hydratase is associated with suppression of miR-200 and the EMT signature in renal cancer and is associated with poor clinical outcome. These results imply that loss of fumarate hydratase and fumarate accumulation contribute to the aggressive features of fumarate hydratase-deficient tumours.

Topics: Animals; Cell Movement; Cells, Cultured; Epigenesis, Genetic; Epithelial-Mesenchymal Transition; Fumarate Hydratase; Fumarates; HEK293 Cells; Humans; Kidney Neoplasms; Mesoderm; Mice; MicroRNAs; Transcription Factors; Transcriptome

Dysregulated metabolism is a hallmark of many diseases, including cancer. Methods to fluorescently detect metabolites have the potential to enable new approaches to cancer detection and imaging. However, fluorescent sensing methods for naturally occurring cellular metabolites are relatively unexplored. Here we report the development of a chemical approach to detect the oncometabolite fumarate. Our strategy exploits a known bioorthogonal reaction, the 1,3-dipolar cycloaddition of nitrileimines and electron-poor olefins, to detect fumarate via fluorescent pyrazoline cycloadduct formation. We demonstrate hydrazonyl chlorides serve as readily accessible nitrileimine precursors, whose reactivity and spectral properties can be tuned to enable detection of fumarate and other dipolarophile metabolites. Finally, we show this reaction can be used to detect enzyme activity changes caused by mutations in fumarate hydratase, which underlie the familial cancer predisposition syndrome hereditary leiomyomatosis and renal cell cancer. Our studies define a novel intersection of bioorthogonal chemistry and metabolite reactivity that may be harnessed to enable biological profiling, imaging, and diagnostic applications.

Topics: Alkenes; Carcinoma, Renal Cell; Fumarate Hydratase; Fumarates; Humans; Imines; Kidney Neoplasms; Molecular Structure

Topics: Adult; Amides; Female; Fumarates; Humans; Juxtaglomerular Apparatus; Kidney Neoplasms; Renin

Notch signaling is a conserved and widely expressed signaling pathway, which mediates various physiological processes including tumorigenesis. This study aims to explore the potential role and mechanism of notch1 interacting with KRT6B in the progression of RCC. The results indicated that the mRNA and protein expression of notch1 and KRT6 were significantly increased in tumor tissues, and highly positive correlation existed between notch1 and KRT6. Moreover, the patients with high notch1 expression had a significantly poorer prognosis than those of low expression patients. In vitro, KRT6 loss-of-function could inhibit the expression of notch1 and induce renal carcinoma cell death. Eventually, we found that renin inhibitor, aliskiren, could inhibit cell proliferation and decrease the expression of notch1 and KRT6 as well as regulate apoptosis-related protein expression in 786-O and ACHN renal carcinoma cell lines. These results suggested that the upregulation of notch1 and KRT6B might be involved in the development, progression and prognosis of human RCC, and aliskiren could suppress renal carcinoma cell proliferation, at least partially, through downregulation the expression of notch1 and KRT6.

Topics: Amides; Apoptosis; Carcinoma, Renal Cell; Cell Line, Tumor; Cell Proliferation; Disease Progression; Female; Fumarates; Gene Silencing; Humans; Keratin-6; Kidney Neoplasms; Male; Middle Aged; Receptor, Notch1; RNA, Small Interfering; Signal Transduction; Up-Regulation

Topics: Carcinoma, Renal Cell; Fumarates; Glutathione; Humans; Kidney Neoplasms; Reactive Oxygen Species

Patients with germline fumarate hydratase (FH) mutation are predisposed to develop aggressive kidney cancer with few treatment options and poor therapeutic outcomes. Activity of the proto-oncogene ABL1 is upregulated in FH-deficient kidney tumors and drives a metabolic and survival signaling network necessary to cope with impaired mitochondrial function and abnormal accumulation of intracellular fumarate. Excess fumarate indirectly stimulates ABL1 activity, while restoration of wild-type FH abrogates both ABL1 activation and the cytotoxicity caused by ABL1 inhibition or knockdown. ABL1 upregulates aerobic glycolysis via the mTOR/HIF1α pathway and neutralizes fumarate-induced proteotoxic stress by promoting nuclear localization of the antioxidant response transcription factor NRF2. Our findings identify ABL1 as a pharmacologically tractable therapeutic target in glycolytically dependent, oxidatively stressed tumors.

Topics: Animals; Cell Line, Tumor; Cell Nucleus; Fumarate Hydratase; Fumarates; Gene Expression Regulation, Neoplastic; Glycolysis; HEK293 Cells; Humans; Kidney Neoplasms; Mice; Neoplasms, Experimental; NF-E2-Related Factor 2; Oxidative Stress; Piperidines; Proto-Oncogene Mas; Proto-Oncogene Proteins c-abl; Quinazolines; Signal Transduction; Xenograft Model Antitumor Assays

The gene encoding the Krebs cycle enzyme fumarate hydratase (FH) is mutated in hereditary leiomyomatosis and renal cell cancer (HLRCC). Loss of FH activity causes accumulation of intracellular fumarate, which can directly modify cysteine residues to form 2-succinocysteine through succination. We undertook a proteomic-based screen in cells and renal cysts from Fh1 (murine FH)-deficient mice and identified 94 protein succination targets. Notably, we identified the succination of three cysteine residues in mitochondrial Aconitase2 (ACO2) crucial for iron-sulfur cluster binding. We show that fumarate exerts a dose-dependent inhibition of ACO2 activity, which correlates with increased succination as determined by mass spectrometry, possibly by interfering with iron chelation. Importantly, we show that aconitase activity is impaired in FH-deficient cells. Our data provide evidence that succination, resulting from FH deficiency, targets and potentially alters the function of multiple proteins and may contribute to the dysregulated metabolism observed in HLRCC.

Topics: Aconitate Hydratase; Animals; Cell Line; Cysteine; Fumarate Hydratase; Fumarates; Humans; Iron; Kidney Neoplasms; Leiomyomatosis; Mice; Mice, Transgenic; Mitochondria; Neoplastic Syndromes, Hereditary; Proteome; Skin Neoplasms; Succinic Acid; Uterine Neoplasms

The identification of mutated metabolic enzymes in hereditary cancer syndromes has established a direct link between metabolic dysregulation and cancer. Mutations in the Krebs cycle enzyme, fumarate hydratase (FH), predispose affected individuals to leiomyomas, renal cysts, and cancers, though the respective pathogenic roles of mitochondrial and cytosolic FH isoforms remain undefined. On the basis of comprehensive metabolomic analyses, we demonstrate that FH1-deficient cells and tissues exhibit defects in the urea cycle/arginine metabolism. Remarkably, transgenic re-expression of cytosolic FH ameliorated both renal cyst development and urea cycle defects associated with renal-specific FH1 deletion in mice. Furthermore, acute arginine depletion significantly reduced the viability of FH1-deficient cells in comparison to controls. Our findings highlight the importance of extramitochondrial metabolic pathways in FH-associated oncogenesis and the urea cycle/arginine metabolism as a potential therapeutic target.

Topics: Animals; Arginine; Argininosuccinic Acid; Cell Line; Citric Acid Cycle; Fumarate Hydratase; Fumarates; Kidney; Kidney Neoplasms; Metabolome; Mice; Mice, Knockout; Mice, Transgenic; Mitochondria; Mutation; Protein Isoforms; Urea

The tricarboxylic acid cycle enzyme fumarate hydratase (FH) has been identified as a tumor suppressor in a subset of human renal cell carcinomas. Human FH-deficient cancer cells display high fumarate concentration and ROS levels along with activation of HIF-1. The underlying mechanisms by which FH loss increases ROS and HIF-1 are not fully understood. Here, we report that glutamine-dependent oxidative citric acid cycle metabolism is required to generate fumarate and increase ROS and HIF-1 levels. Accumulated fumarate directly bonds the antioxidant glutathione in vitro and in vivo to produce the metabolite succinated glutathione (GSF). GSF acts as an alternative substrate to glutathione reductase to decrease NADPH levels and enhance mitochondrial ROS and HIF-1 activation. Increased ROS also correlates with hypermethylation of histones in these cells. Thus, fumarate serves as a proto-oncometabolite by binding to glutathione which results in the accumulation of ROS.

Topics: Carcinoma, Renal Cell; Chromatography, Liquid; Fumarate Hydratase; Fumarates; Glutathione; Glutathione Reductase; Histone Demethylases; Histones; Humans; Hypoxia-Inducible Factor 1, alpha Subunit; Immunoblotting; Kidney Neoplasms; NADP; NF-E2-Related Factor 2; Oxygen Consumption; Reactive Oxygen Species; RNA, Small Interfering; Signal Transduction; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Tumor Cells, Cultured

Topics: Adult; Amides; Female; Fumarates; Humans; Juxtaglomerular Apparatus; Kidney Neoplasms; Renin

Loss-of-function mutations of the tumor suppressor gene encoding fumarase (FH) occur in individuals with hereditary leiomyomatosis and renal cell cancer syndrome (HLRCC). We found that loss of FH activity conferred protection from apoptosis in normal human renal cells and fibroblasts. In FH-defective cells, both hypoxia-inducible factor 1α (HIF-1α) and HIF-2α accumulated, but they were not required for apoptosis protection. Conversely, AMP-activated protein kinase (AMPK) was activated and required, as evidenced by the finding that FH inactivation failed to protect AMPK-null mouse embryo fibroblasts (MEFs) and AMPK-depleted human renal cells. Activated AMPK was detected in renal cysts, which occur in mice with kidney-targeted deletion of Fh1 and in kidney cancers of HLRCC patients. In Fh1-null MEFs, AMPK activation was sustained by fumarate accumulation and not by defective energy metabolism. Addition of fumarate and succinate to kidney cells led to extracellular signal-regulated kinase 1/2 (ERK1/2) and AMPK activation, probably through a receptor-mediated mechanism. These findings reveal a new mechanism of tumorigenesis due to FH loss and an unexpected pro-oncogenic role for AMPK that is important in considering AMPK reactivation as a therapeutic strategy against cancer.

Topics: AMP-Activated Protein Kinases; Animals; Apoptosis; Basic Helix-Loop-Helix Transcription Factors; Cell Line; Fumarate Hydratase; Fumarates; Humans; Hypoxia-Inducible Factor 1, alpha Subunit; Kidney Neoplasms; Leiomyomatosis; Mice; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Neoplastic Syndromes, Hereditary; Reactive Oxygen Species; RNA Interference; RNA, Small Interfering; Signal Transduction; Skin Neoplasms; Tumor Suppressor Proteins; Uterine Neoplasms

Fumarate hydratase (FH) is an enzyme of the tricarboxylic acid cycle (TCA cycle) that catalyses the hydration of fumarate into malate. Germline mutations of FH are responsible for hereditary leiomyomatosis and renal-cell cancer (HLRCC). It has previously been demonstrated that the absence of FH leads to the accumulation of fumarate, which activates hypoxia-inducible factors (HIFs) at normal oxygen tensions. However, so far no mechanism that explains the ability of cells to survive without a functional TCA cycle has been provided. Here we use newly characterized genetically modified kidney mouse cells in which Fh1 has been deleted, and apply a newly developed computer model of the metabolism of these cells to predict and experimentally validate a linear metabolic pathway beginning with glutamine uptake and ending with bilirubin excretion from Fh1-deficient cells. This pathway, which involves the biosynthesis and degradation of haem, enables Fh1-deficient cells to use the accumulated TCA cycle metabolites and permits partial mitochondrial NADH production. We predicted and confirmed that targeting this pathway would render Fh1-deficient cells non-viable, while sparing wild-type Fh1-containing cells. This work goes beyond identifying a metabolic pathway that is induced in Fh1-deficient cells to demonstrate that inhibition of haem oxygenation is synthetically lethal when combined with Fh1 deficiency, providing a new potential target for treating HLRCC patients.

Topics: Animals; Bilirubin; Cell Line; Cells, Cultured; Citric Acid Cycle; Computer Simulation; Fumarate Hydratase; Fumarates; Genes, Lethal; Genes, Tumor Suppressor; Glutamine; Heme; Heme Oxygenase (Decyclizing); Kidney Neoplasms; Leiomyomatosis; Mice; Mitochondria; Mutation; NAD; Neoplastic Syndromes, Hereditary; Skin Neoplasms; Uterine Neoplasms

In eukaryotes, fumarase (FH in human) is a well-known tricarboxylic-acid-cycle enzyme in the mitochondrial matrix. However, conserved from yeast to humans is a cytosolic isoenzyme of fumarase whose function in this compartment remains obscure. A few years ago, FH was surprisingly shown to underlie a tumor susceptibility syndrome, Hereditary Leiomyomatosis and Renal Cell Cancer (HLRCC). A biallelic inactivation of FH has been detected in almost all HLRCC tumors, and therefore FH was suggested to function as a tumor suppressor. Recently it was suggested that FH inhibition leads to elevated intracellular fumarate, which in turn acts as a competitive inhibitor of HPH (HIF prolyl hydroxylase), thereby causing stabilization of HIF (Hypoxia-inducible factor) by preventing proteasomal degradation. The transcription factor HIF increases the expression of angiogenesis regulated genes, such as VEGF, which can lead to high microvessel density and tumorigenesis. Yet this mechanism does not fully explain the large cytosolic population of fumarase molecules. We constructed a yeast strain in which fumarase is localized exclusively to mitochondria. This led to the discovery that the yeast cytosolic fumarase plays a key role in the protection of cells from DNA damage, particularly from DNA double-strand breaks. We show that the cytosolic fumarase is a member of the DNA damage response that is recruited from the cytosol to the nucleus upon DNA damage induction. This function of fumarase depends on its enzymatic activity, and its absence in cells can be complemented by high concentrations of fumaric acid. Our findings suggest that fumarase and fumaric acid are critical elements of the DNA damage response, which underlies the tumor suppressor role of fumarase in human cells and which is most probably HIF independent. This study shows an exciting crosstalk between primary metabolism and the DNA damage response, thereby providing a scenario for metabolic control of tumor propagation.

Topics: Cell Nucleus; Cytosol; DNA Damage; Fumarate Hydratase; Fumarates; Gene Knockdown Techniques; HeLa Cells; Histones; Humans; Hypoxia-Inducible Factor 1, alpha Subunit; Isoenzymes; Kidney Neoplasms; Leiomyomatosis; Mitochondria; Saccharomyces cerevisiae; Saccharomyces cerevisiae Proteins; Tumor Suppressor Proteins

Individuals with hemizygous germline fumarate hydratase (FH) mutations are predisposed to renal cancer. These tumors predominantly exhibit functional inactivation of the remaining wild-type allele, implicating FH inactivation as a tumor-promoting event. Hypoxia-inducible factors are expressed in many cancers and are increased in clear cell renal carcinomas. Under normoxia, the HIFs are labile due to VHL-dependent proteasomal degradation, but stabilization occurs under hypoxia due to inactivation of HIF prolyl hydroxylase (HPH), which prevents HIF hydroxylation and VHL recognition. We demonstrate that FH inhibition, together with elevated intracellular fumarate, coincides with HIF upregulation. Further, we show that fumarate acts as a competitive inhibitor of HPH. These data delineate a novel fumarate-dependent pathway for regulating HPH activity and HIF protein levels.

Topics: Adult; Alleles; Basic Helix-Loop-Helix Transcription Factors; Carcinoma, Renal Cell; DNA-Binding Proteins; Female; Fumarate Hydratase; Fumarates; Gene Expression Regulation, Neoplastic; Humans; Hypoxia-Inducible Factor 1; Hypoxia-Inducible Factor 1, alpha Subunit; Ketoglutaric Acids; Kidney Neoplasms; Leiomyomatosis; Male; Middle Aged; Nuclear Proteins; Procollagen-Proline Dioxygenase; Syndrome; Transcription Factors; Up-Regulation

Anticarcinogenic effects of the fumaric acid was studied in two rat models of carcinogenesis. Tumors of the esophagus, forestomach, tongue and throat were induced by peroral instillation of 35 mg/kg body weight N-methyl-N-benzylnitrosamine, and neurogenic and renal ones--by transplacental injection of 75 mg/kg body weight N-ethyl-N-nitrosourea. The fumaric acid given in drinking water in the dose of 1 g/l at the postinitiation stage of the carcinogenesis was shown to inhibit the development of esophageal papilloma, brain glioma and mesenchymal tumors of the kidney.

Topics: Animals; Anticarcinogenic Agents; Carcinogens; Chi-Square Distribution; Dimethylnitrosamine; Disease Models, Animal; Drug Screening Assays, Antitumor; Esophageal Neoplasms; Ethylnitrosourea; Female; Fumarates; Kidney Neoplasms; Male; Nervous System Neoplasms; Pregnancy; Prenatal Exposure Delayed Effects; Rats